Sue Llewellyn asks if there’s a way to filter out Foursquare tweets. There is.

The first thing to do is work out something that all the tweets share. Well, every Foursquare tweet includes a link that begins http://4sq.com – so that’s it.

If you’re using Tweetdeck this is how you do it. At the bottom of every column in Tweetdeck are 6 buttons. The second one in – a downward-pointing arrow – is the ‘Filter this column’ button. Click this. A new row appears where you can filter the tweets. Select ‘Text’ then ‘-‘ and type ‘http://4sq.com’ in the third box. You should see tweets automatically filtered accordingly.

Seesmic desktop has a similar filtering function.

And on iPhone a few Twitter clients have filtering options, including Twittelator.

Let me know if you know of any others.